An implant that regenerates tissue after surgery to treat a herniated disc is developed by French scientists, a breakthrough that could potentially prevent the formation of other painful growths.
People who suffer from severe herniated discs sometimes have to be operated on to reduce back pain.
This procedure leaves damaged tissue that can eventually lead to the appearance of new hernias.
- A hernia is an outgrowth of an organ or organ part out of its usual position. A disc herniation concerns the portion of an intervertebral disc.
- It causes back pain by compressing a nerve in the spine, a suffering that is exacerbated as soon as it solicits the back muscles.
- The rings of fibrous cartilage ( Annulus fibrosus ), which are discussed in the present work, are the discs consisting of rather dense fibrous cartilage surrounding the nucleus pulposus located between two non-welded vertebrae.
- These rings, which are in some way the envelope surrounding the nucleus pulposus, strongly adhere to the vertebrae. They ensure the stability of the spine and absorb the pressure and distribute the shocks and tensions that are exerted on the vertebrae.
- Most of the time, herniated discs are treated without surgery. An operation is necessary in less than 20% of cases.
A painful problem
A herniated disc can be very bothersome, especially when it originates from the compression of a nerve at the level of the five lumbar vertebrae.
Usually, the cartilage rings between each of the vertebrae are supposed to cushion the shocks while providing some flexibility to the spine. However, as a result of repeated solicitations, trauma or false movements, these rings can crack and let the nucleus contents pulp out.
This can then compress nerve roots and thus cause pain in the back, but also in the legs if the sciatic nerve is affected. Sciatica can cause paralysis of the lower limbs and incontinence.
Catherine Le Visage, Laboratory Regenerative Medicine and Skeleton at the University of Nantes
In more severe cases, doctors often opt for a surgical procedure to remove the part of the nucleus pulposus that compresses the nerve, which usually relieves patients.
This procedure, however, causes a tear in the fibrous ring, which may eventually cause further herniation and lead to further deterioration of the intervertebral disc.
A “structuring” implant
The French team has developed an implant that mimics the concentric structure of fibrous cartilage rings.
It is composed of an assembly of lamellae, themselves constituted by a porous network of aligned fibers of polycaprolactone, a biodegradable material commonly used in the medical field.
Dr. Catherine Le Visage and her colleagues hoped that by mimicking the ring structure of the rings, the cells colonize the implant and regenerate the damaged tissue.
In animal models, their expectations have been met.
We were surprised to see that the implant integrated so quickly into the surrounding tissue.
Catherine The Face
“In just one month, the ring cells proliferated while producing collagen. However, it is this protein that forms the cartilage of the fibrous ring and allows it to limit the expansion of the nucleus pulposus, “says Ms. Visage.
These results excite the authors of these works published in the journal Biomaterials (New Window ). They now want to adapt the degradation of the implant material to the rapid tissue regeneration.
Researchers must also verify whether the regenerated tissues can limit the appearance of new hernias and the phenomenon of degeneration of the intervertebral disc. If that’s the case, clinical trials could go forward in humans.
The biomimetic implant could possibly be proposed to patients undergoing surgery for a herniated disc in order to reduce the risk of seeing it reappear one day.
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